Sand mixing and liquid supplying method and fracturing blender truck

Abstract

The invention discloses a sand mixing and liquid supplying method and a sand mixing truck, and relates to the technical field of solid-liquid mixed materials. The sand mixing and liquid supplying method comprises the steps that a liquid suction pump is started to suck mixed liquid into a mixing tank; the liquid level height in the mixing tank is obtained, and whether the liquid level height is larger than or equal to a first preset height or not is judged; starting a liquid discharge pump according to the judgment result, and obtaining the liquid discharge rotating speed of the liquid discharge pump; and the liquid suction rotating speed of the liquid suction pump is adjusted according to the liquid discharging rotating speed, so that the liquid level height tends to a second preset height. According to the technical scheme, the stability of the liquid level in the mixing tank can be guaranteed, the stability in the sand mixing process is improved, and the technical effect of continuously outputting high-quality mixed materials is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of solid-liquid mixed material processing, in particular to a sand mixing and liquid supply method and a sand mixing vehicle. Background Art

[0002] Generally, existing sand blending trucks are provided with "manual / automatic" buttons for the engine, suction pump, discharge pump, mixing tank, etc. The "automatic" button controls the liquid supply system through a program.

[0003] However, in the prior art, in some systems, the engine preparation, suction pump control, and discharge pump control are independent of each other during the operation preparation process, and the operation is cumbersome. Operators are required to monitor the parameters of each system in real time. In some systems, only a single parameter is used to control the opening and closing of the suction pump or the discharge pump. During long-term operation, the liquid level in the mixing tank fluctuates greatly and cannot be kept stable. Too much or too little liquid can easily affect the quality of the product, and frequent system switching can easily reduce the life of the equipment. Summary of the invention

[0004] The main purpose of the present invention is to propose a sand mixing and liquid supply method and a sand mixing vehicle, aiming to solve the technical problems in the prior art that during long-term operation, the liquid level in the mixing tank fluctuates greatly and cannot be kept stable, and the frequent switching of the system easily leads to a reduction in equipment life.

[0005] To achieve the above object, the present invention provides a sand mixing and liquid supply method, the sand mixing and liquid supply method comprising:

[0006] Turn on the suction pump to suck the mixed liquid into the mixing tank;

[0007] Obtaining the liquid level in the mixing tank, and determining whether the liquid level is greater than or equal to a first preset height;

[0008] Starting the liquid discharge pump according to the judgment result, and obtaining the liquid discharge speed of the liquid discharge pump;

[0009] The liquid suction speed of the liquid suction pump is adjusted according to the liquid discharge speed so that the liquid level approaches a second preset height.

[0010] In one embodiment, the step of starting the liquid discharge pump according to the judgment result and obtaining the liquid discharge speed of the liquid discharge pump includes:

[0011] When the liquid level is greater than or equal to the first preset height, starting the liquid discharge pump;

[0012] The rotation speed of the liquid discharge pump is controlled to gradually increase by a first change value in each cycle, and the rotation speed of the liquid discharge pump is acquired in real time as the liquid discharge rotation speed.

[0013] In one embodiment, the step of adjusting the suction speed of the suction pump according to the discharge speed includes:

[0014] Obtaining a change trend of the liquid discharge rotation speed;

[0015] When the change trend is an increasing trend, controlling the liquid aspiration speed to gradually increase the second change value in each cycle;

[0016] When the change trend is a decreasing trend, the liquid aspiration speed is controlled to gradually decrease the second change value in each cycle.

[0017] In one embodiment, the step of obtaining the change trend of the liquid discharge speed includes:

[0018] Obtain the liquid discharge speed corresponding to the previous moment and the current moment respectively;

[0019] Calculating the difference between the liquid discharge speed corresponding to the previous moment and the liquid discharge speed corresponding to the current moment;

[0020] Determine the change trend according to the difference;

[0021] Therein, the previous moment and the current moment are separated by a first preset time length.

[0022] In one embodiment, after the step of starting the liquid discharge pump according to the judgment result and obtaining the liquid discharge speed of the liquid discharge pump, the method further includes:

[0023] Obtaining the liquid outlet pressure of the liquid outlet of the liquid discharge pump;

[0024] The liquid discharge speed is adjusted according to the liquid outlet pressure so that the liquid outlet pressure approaches a preset pressure.

[0025] In one embodiment, after the step of adjusting the suction speed of the suction pump according to the discharge speed, the method further includes:

[0026] Determining whether the liquid level is greater than or equal to a third preset height, and determining whether the liquid level is less than a fourth preset height;

[0027] When the liquid level is greater than or equal to the third preset height, the liquid discharge speed is kept unchanged and the liquid suction speed is reduced;

[0028] When the liquid level is less than the fourth preset height, the liquid discharge speed is kept unchanged and the liquid suction speed is increased;

[0029] The third preset height is greater than the second preset height, and the fourth preset height is less than the second preset height.

[0030] In one embodiment, when the liquid level is greater than or equal to the second preset height, the step of maintaining the liquid discharge speed unchanged and reducing the liquid suction speed includes:

[0031] When the liquid level is greater than or equal to the third preset height, the liquid discharge speed is kept unchanged, the current speed of the liquid suction pump is recorded, and the liquid suction speed is reduced;

[0032] Determine whether the liquid level has reached the second preset height, and when the liquid level has reached the second preset height, restore the liquid suction speed to the current speed.

[0033] In one embodiment, when the liquid level is less than the fourth preset height, the liquid discharge speed is kept unchanged, and the step of increasing the liquid suction speed includes:

[0034] When the liquid level height is less than the fourth preset height, the liquid discharge speed is kept unchanged, the current speed of the liquid suction pump is recorded, and the liquid suction speed is increased;

[0035] Determine whether the liquid level has reached the second preset height, and when the liquid level has reached the second preset height, restore the liquid suction speed to the current speed.

[0036] In one embodiment, before the step of starting the liquid suction pump to suck the mixed liquid into the mixing tank, the method further comprises:

[0037] Starting the engine and obtaining the engine speed;

[0038] Determining whether the engine speed is greater than or equal to a preset speed;

[0039] When the engine speed is greater than or equal to the preset speed, the step of "starting the liquid suction pump to suck the mixed liquid into the mixing tank" is performed.

[0040] In order to solve the above problems, the present invention further proposes a sand blending vehicle, which comprises:

[0041] A vehicle body, wherein a mixing tank is provided on the vehicle body, one end of the mixing tank is connected to a liquid suction pump, and the other end of the mixing tank is connected to a liquid discharge pump;

[0042] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the sand mixing and liquid supply method as described above.

[0043] The technical solution of the present invention first needs to determine the timing of starting the liquid discharge pump to ensure that there is enough liquid material in the mixing tank for sand mixing operations, and to ensure that the efficiency of the sand mixing process and the quality of the mixed materials can meet the requirements. After turning on the liquid discharge pump, the speed of the liquid suction pump is adjusted in real time according to the liquid discharge speed of the liquid discharge pump, so that the liquid level in the mixing tank can be adjusted from the first preset height to the second preset height, and maintained at the second preset height throughout the operation process. Ensure the stability of the liquid level in the mixing tank, improve the stability during the sand mixing process, and continuously output high-quality mixed materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0045] Figure 1 A schematic structural diagram of a first embodiment of the sand mixing and liquid supply method provided by the present invention;

[0046] Figure 2 A schematic structural diagram of a second embodiment of the sand mixing and liquid supply method provided by the present invention;

[0047] Figure 3 A schematic structural diagram of a third embodiment of the sand mixing and liquid supply method provided by the present invention;

[0048] Figure 4 A schematic structural diagram of a fourth embodiment of the sand mixing and liquid supply method provided by the present invention;

[0049] Figure 5 A schematic structural diagram of a fifth embodiment of the sand mixing and liquid supply method provided by the present invention;

[0050] Figure 6 This is a schematic structural diagram of a sixth embodiment of the sand mixing and liquid supply method provided by the present invention.

[0051] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0054] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0055] The invention provides a sand mixing and liquid supply method.

[0056] Please refer to Figure 1 In the first embodiment of the present invention, the sand mixing and liquid supply method comprises the following steps:

[0057] Step S10: Turn on the liquid suction pump to suck the mixed liquid into the mixing tank;

[0058] Step S20: obtaining the liquid level in the mixing tank, and determining whether the liquid level is greater than or equal to a first preset height;

[0059] Step S30: starting the liquid discharge pump according to the judgment result, and obtaining the liquid discharge speed of the liquid discharge pump;

[0060] Step S40: adjusting the liquid suction speed of the liquid suction pump according to the liquid discharge speed so that the liquid level approaches a second preset height.

[0061] When mixing sand, the operator turns on the mixing system by pressing the corresponding start button. The mixing system includes multiple pipelines, and the mixing tank has multiple material holes, which are connected to different external devices through pipelines. Among them, the external devices may include but are not limited to: liquid supply equipment for increasing liquid material, material unloading equipment for recovering materials after the mixing operation is completed, and recovery equipment for recovering waste liquid. The suction pump and the discharge pump are respectively arranged on the corresponding pipelines.

[0062] The sand mixing system also includes a controller, such as a PLC controller, which can be connected to the signals of the suction pump, the discharge pump and other equipment. After the sand mixing system is turned on, the suction pump is turned on, and the suction pump runs at the initial suction speed to suck the liquid into the mixing tank. A liquid level detection sensor can be set in the mixing tank to detect the liquid level in the mixing tank in real time, and feed the liquid level back to the controller. The controller determines whether the liquid level reaches the first preset height. When the first preset height is reached, the controller automatically controls the discharge pump to start.

[0063] It should be noted that when the liquid suction speed is higher, the flow rate of the liquid material entering the mixing tank through the pipeline is higher, and when the liquid suction speed is lower, the flow rate of the liquid material entering the mixing tank through the pipeline is lower. Similarly, when the liquid discharge speed is higher, the flow rate of the liquid material flowing out of the mixing tank through the pipeline is higher, and when the liquid discharge speed is lower, the flow rate of the liquid material flowing out of the mixing tank through the pipeline is lower.

[0064] Among them, the first preset height can be set to 50% of the total height of the mixing tank, and can be adjusted accordingly according to the total volume of the mixing tank, so as to avoid the risks of overflowing in the mixing tank and dry grinding due to insufficient liquid.

[0065] After the liquid discharge pump is turned on, its liquid discharge speed gradually increases from 0 to the preset initial liquid discharge speed. It can be understood that in the process of increasing the liquid discharge speed from 0 to the initial liquid discharge speed, the liquid enters the mixing tank faster, so it is necessary to appropriately adjust the liquid suction speed according to the liquid discharge speed to maintain the liquid level in the mixing tank stable.

[0066] When the initial speed of liquid discharge is reached, the speed of liquid discharge is further increased, and the speed of liquid suction is adjusted accordingly according to the speed of liquid discharge to improve the efficiency of sand mixing. By controlling the coordination between the speed of liquid discharge and the speed of liquid suction, the liquid level in the mixing tank is maintained with small fluctuations near the second preset height. The second preset height can be adjusted according to the specific overall capacity or size of the mixing tank. For example, the second preset height can be any value between 40% and 80% of the total height of the mixing tank. In addition, the second preset height can also be set as a range value so that the liquid level fluctuates cyclically within the range of the second preset height.

[0067] The technical solution of the present invention first needs to determine the timing of starting the liquid discharge pump to ensure that there is enough liquid material in the mixing tank for sand mixing operations, and to ensure that the efficiency of the sand mixing process and the quality of the mixed materials can meet the requirements. After turning on the liquid discharge pump, the speed of the liquid suction pump is adjusted in real time according to the liquid discharge speed of the liquid discharge pump, so that the liquid level in the mixing tank can be adjusted from the first preset height to the second preset height, and maintained at the second preset height throughout the operation process. Ensure the stability of the liquid level in the mixing tank, improve the stability during the sand mixing process, and continuously output high-quality mixed materials.

[0068] Please refer to Figure 2 In the second embodiment of the present invention, step S30 specifically includes the following steps:

[0069] Step S31: when the liquid level is greater than or equal to the first preset height, start the liquid discharge pump;

[0070] Step S32: Control the rotation speed of the liquid discharge pump to gradually increase by a first change value in each cycle, and obtain the rotation speed of the liquid discharge pump in real time as the liquid discharge rotation speed.

[0071] When the liquid level is greater than or equal to the first preset height, the liquid discharge speed is controlled to increase by a first change value in a periodic increasing manner for each period of time. For example, 0.1 min is taken as a period and 50 r / min is taken as the first change value, that is, the liquid discharge speed increases by 50 r / min for each 0.1 min.

[0072] The discharge speed is controlled in a periodic increasing manner so that the discharge pump and the suction pump have a reasonable operating curve, further improving the operating accuracy and stability.

[0073] Please refer to Figure 3 In the third embodiment of the present invention, step S40 specifically includes the following steps:

[0074] Step S41: obtaining the change trend of the liquid discharge speed;

[0075] Step S42: when the change trend is an increasing trend, controlling the liquid aspiration speed to gradually increase the second change value in each cycle;

[0076] Step S43: When the change trend is a decreasing trend, the liquid aspiration speed is controlled to gradually decrease the second change value in each cycle.

[0077] In this embodiment, the change trend of the liquid discharge speed can be directly obtained to control the liquid suction speed in advance and adjust it accordingly.

[0078] Similarly, when increasing or decreasing the liquid aspiration speed, the liquid discharge speed is controlled to increase or decrease by the second change value every time a cycle passes in a periodic increasing or periodic decreasing manner.

[0079] The second change value and the first change value can be set to be the same, or can be adjusted accordingly according to specific circumstances. The liquid suction speed is controlled in a periodic increasing or decreasing manner, so that the liquid discharge pump and the liquid suction pump have a reasonable operating curve, further improving the operating accuracy and stability.

[0080] Specifically, the change trend can be determined by collecting the liquid discharge speed one by one according to the time frame. Step S41 specifically includes:

[0081] Step S411: obtaining the liquid discharge speed corresponding to the previous moment and the current moment respectively;

[0082] Step S412: calculating the difference between the liquid discharge speed corresponding to the previous moment and the liquid discharge speed corresponding to the current moment;

[0083] Step S413: Determine the change trend according to the difference.

[0084] Among them, the interval between the two moments, that is, the first preset duration, can be determined according to the time frame resolution. In this embodiment, the interval between the two moments is 1 second as an example. That is, the corresponding discharge speed at the current moment and the corresponding discharge speed at the last second are collected respectively, and the difference between them is calculated. When the corresponding discharge speed at the last second is less than the corresponding discharge speed at the current moment, it indicates that the change trend is an increasing trend. On the contrary, it is a decreasing trend.

[0085] In order to ensure reliability, in this embodiment, the corresponding discharge speeds at at least three moments may be collected. Alternatively, the corresponding discharge speeds at four moments or five moments may be collected. When the discharge speeds at at least three consecutive moments gradually increase, the change trend is determined to be an increasing trend, thereby avoiding misjudgment. In addition, the first preset time length may also be set to, for example, 2 seconds, 3 seconds, etc.

[0086] Please refer to Figure 4 In the fourth embodiment of the present invention, after step S30, the method further includes:

[0087] Step S50: obtaining the outlet pressure of the liquid at the outlet of the liquid discharge pump;

[0088] Step S60: adjusting the liquid discharge speed according to the liquid outlet pressure so that the liquid outlet pressure approaches a preset pressure.

[0089] In order to ensure the safety of the sand mixing system during operation, a pressure sensor is provided in the external device or pipeline connected to the liquid outlet of the discharge pump to detect the outlet pressure of the liquid in the device or pipeline.

[0090] When the outlet pressure is too high, it may cause the pipeline to rupture or the equipment to be damaged. When the outlet pressure is too low, it may cause the liquid to be unable to be discharged normally. Therefore, in this embodiment, the outlet pressure is maintained at about the preset pressure by adjusting the liquid discharge speed.

[0091] Specifically, in order to further ensure the safety during operation, the preset pressure is the optimal value of the liquid outlet pressure after the test. At the same time, the maximum pressure value, the minimum pressure value and the normal pressure value are set. When the liquid outlet pressure is greater than the maximum pressure value, the liquid discharge speed is reduced accordingly, and the liquid discharge flow rate is reduced. On the contrary, when the liquid outlet pressure is less than the minimum pressure value, the liquid discharge speed is increased accordingly. It should be noted that when the liquid discharge speed is reduced, the liquid suction speed should be adjusted accordingly to ensure the stability of the liquid level in the mixing tank. And preset.

[0092] In this embodiment, the maximum pressure value can be set to 110% of the preset pressure, and the minimum pressure value can be set to 90% of the preset pressure value.

[0093] Please refer to Figure 5 In the fifth embodiment of the present invention, after step S40, the method further includes:

[0094] Step S70: determining whether the liquid level is greater than or equal to a third preset height, and determining whether the liquid level is less than a fourth preset height;

[0095] Step S80: when the liquid level is greater than or equal to the third preset height, the liquid discharge speed is kept unchanged and the liquid suction speed is reduced;

[0096] Step S90: When the liquid level is less than the fourth preset height, the liquid discharge speed is kept unchanged and the liquid suction speed is increased.

[0097] In order to further improve the safety and reliability of the sand mixing system during operation, the third preset height is set as the highest warning water level in the mixing tank, and the fourth preset height is set as the lowest warning water level. This prevents the liquid from overflowing the mixing tank due to the high liquid level, and prevents the mixing tank from dry grinding due to the low liquid level.

[0098] In this embodiment, when the liquid level is greater than the third preset height, in order to reduce the liquid level as quickly as possible, the liquid discharge speed is kept unchanged so as to discharge the liquid in the mixing tank as quickly as possible. At the same time, the liquid suction speed is reduced, thereby reducing the liquid entering the mixing tank and achieving the effect of reducing the liquid level. Correspondingly, when the liquid level is less than the fourth preset height, the liquid discharge speed is also kept unchanged, and the liquid suction speed is increased.

[0099] Among them, the third preset height is greater than the second preset height, and the fourth preset height is less than the second preset height.

[0100] Specifically, to ensure that the mixing tank can operate continuously and stably, when the liquid level drops from the highest warning water level and returns to the optimal water level, that is, after it drops to the second preset height, the liquid suction speed should be restored to the original speed.

[0101] That is, when the liquid level reaches the third preset height, the current rotation speed of the liquid suction pump is recorded, the liquid discharge rotation speed is kept unchanged, and the liquid suction rotation speed is reduced.

[0102] When it is determined that the liquid level is lowered to the second preset height, when the liquid level reaches the second preset height, the liquid suction speed is restored to the current speed.

[0103] Correspondingly, when the liquid level rises from the lowest warning water level to the optimal water level, that is, after it rises to the second preset height, the liquid suction speed should be restored to the original speed.

[0104] That is, when the liquid level is less than the fourth preset height, the discharge speed is kept unchanged, the current speed of the suction pump is recorded, and the suction speed is increased; it is determined whether the liquid level has reached the second preset height, and when the liquid level reaches the second preset height, the suction speed is restored to the current speed.

[0105] Please refer to Figure 6 In the sixth embodiment of the present invention, before step S10, the method further includes:

[0106] Step S100: starting the engine and obtaining the engine speed;

[0107] Step S110: determining whether the engine speed is greater than or equal to a preset speed;

[0108] Step S120: When the engine speed is greater than or equal to the preset speed, execute step S10.

[0109] Before sand mixing, the discharge pump and suction pump need to be connected to the water pipes, and the valves of each pipe need to be opened.

[0110] When the operator turns on the sand mixing system through the control button, the engine is directly controlled to increase the speed to the rated speed according to the most appropriate program. Then the suction pump is turned on accordingly. The whole process is determined by automation, so that the operator can truly "supply liquid with one button". It improves the convenience of the operator's operation, improves the operation efficiency, and reduces the labor intensity of the operation.

[0111] The present invention also proposes a sand blending truck, which includes a vehicle body, a mixing tank on which one end of the mixing tank is connected to a suction pump and the other end is connected to a discharge pump; a memory, a processor, and a computer program stored in the memory and executable on the processor.

[0112] The specific structure of the sand mixing and liquid supply method refers to the above embodiments. Since the sand mixing vehicle adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0113] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A sand mixing and liquid supply method, characterized in that: The sand mixing and liquid supply method comprises: Turn on the suction pump to suck the mixed liquid into the mixing tank; Obtaining the liquid level in the mixing tank, and determining whether the liquid level is greater than or equal to a first preset height; Starting the liquid discharge pump according to the judgment result, and obtaining the liquid discharge speed of the liquid discharge pump; The liquid suction speed of the liquid suction pump is adjusted according to the liquid discharge speed so that the liquid level approaches a second preset height.

2. The sand mixing and liquid supply method according to claim 1, characterized in that: The steps of starting the liquid discharge pump according to the judgment result and obtaining the liquid discharge speed of the liquid discharge pump include: When the liquid level is greater than or equal to the first preset height, starting the liquid discharge pump; The rotation speed of the liquid discharge pump is controlled to gradually increase by a first change value in each cycle, and the rotation speed of the liquid discharge pump is acquired in real time as the liquid discharge rotation speed.

3. The sand mixing and liquid supply method according to claim 1, characterized in that: The step of adjusting the suction speed of the suction pump according to the discharge speed comprises: Obtaining a change trend of the liquid discharge rotation speed; When the change trend is an increasing trend, controlling the liquid aspiration speed to gradually increase the second change value in each cycle; When the change trend is a decreasing trend, the liquid aspiration speed is controlled to gradually decrease the second change value in each cycle.

4. The sand mixing and liquid supply method according to claim 3, characterized in that: The step of obtaining the change trend of the liquid discharge speed comprises: Obtain the liquid discharge speed corresponding to the previous moment and the current moment respectively; Calculating the difference between the liquid discharge speed corresponding to the previous moment and the liquid discharge speed corresponding to the current moment; Determine the change trend according to the difference; Therein, the previous moment and the current moment are separated by a first preset time length.

5. The sand mixing and liquid supply method according to claim 1, characterized in that: After the step of starting the liquid discharge pump according to the judgment result and obtaining the liquid discharge speed of the liquid discharge pump, the method further includes: Obtaining the liquid outlet pressure of the liquid outlet of the liquid discharge pump; The liquid discharge speed is adjusted according to the liquid outlet pressure so that the liquid outlet pressure approaches a preset pressure.

6. The sand mixing and liquid supply method according to claim 1, characterized in that: After the step of adjusting the suction speed of the suction pump according to the discharge speed, the method further includes: Determining whether the liquid level is greater than or equal to a third preset height, and determining whether the liquid level is less than a fourth preset height; When the liquid level is greater than or equal to the third preset height, the liquid discharge speed is kept unchanged and the liquid suction speed is reduced; When the liquid level is less than the fourth preset height, the liquid discharge speed is kept unchanged and the liquid suction speed is increased; The third preset height is greater than the second preset height, and the fourth preset height is less than the second preset height.

7. The sand mixing and liquid supply method according to claim 6, characterized in that: When the liquid level is greater than or equal to the second preset height, the step of maintaining the liquid discharge speed unchanged and reducing the liquid suction speed comprises: When the liquid level is greater than or equal to the third preset height, the liquid discharge speed is kept unchanged, the current speed of the liquid suction pump is recorded, and the liquid suction speed is reduced; Determine whether the liquid level has reached the second preset height, and when the liquid level has reached the second preset height, restore the liquid suction speed to the current speed.

8. The sand mixing and liquid supply method according to claim 6, characterized in that: When the liquid level is less than the fourth preset height, the step of maintaining the liquid discharge speed unchanged and increasing the liquid suction speed comprises: When the liquid level height is less than the fourth preset height, the liquid discharge speed is kept unchanged, the current speed of the liquid suction pump is recorded, and the liquid suction speed is increased; Determine whether the liquid level has reached the second preset height, and when the liquid level has reached the second preset height, restore the liquid suction speed to the current speed.

9. The sand mixing and liquid supply method according to claim 1, characterized in that: Before the step of starting the liquid suction pump to suck the mixed liquid into the mixing tank, the step further includes: Starting the engine and obtaining the engine speed; Determining whether the engine speed is greater than or equal to a preset speed; When the engine speed is greater than or equal to the preset speed, the step of "starting the liquid suction pump to suck the mixed liquid into the mixing tank" is performed.

10. A sand blender, characterized in that: The sand blender comprises: A vehicle body, wherein a mixing tank is provided on the vehicle body, one end of the mixing tank is connected to a liquid suction pump, and the other end of the mixing tank is connected to a liquid discharge pump; A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the sand mixing and liquid supply method according to any one of claims 1 to 9.

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